Recently I made a skim through ports collection and search using Google to find application or applet for KDE which I can use to view + select + connect/disconnect to the access point I wish.
Currently I frequently visit few wireless networks and fixed one. I would like to get some flexibility in selection. Not just stick to one configuration and in other cases do all connection matters by hand.

If it can work like in SuSe or Vista, it should be great! Does anybody knows such an application? Or what experience you have treating this problem?

Try sysutils/desktopbsd-tools. Among other things, it includes an applet that lets you control your network connections. You can configure your network through a tray icon or a panel in the KDE Control Center.

Yup, that desktopbsd piece of software works, but it is still rough at the edges. Or may be my Intel 3945ABG wireless card is not good at working with current drivers... who knows.
I wouldn't recommend this software for a beginner. There are still a list of things that should be understood and then done. Anyway, courage in BSD world is always welcome.
Installed, this software really simplifies desktop life.

Shell script? Thanks, but I think it's not the right place for this. When I log into KDE, I don't want to open the shell just to connect for one or more networks. However, I admit that this can work well for to specifical networks.
And.. I think this will be the only way out, because currently the desktopbsd nettray app is not very good at connection to networks. Sometimes it just simply doesn't work!